Merge d3b6304 into e6a8283

src/filters.rs

@@ -17,6 +17,7 @@ pub enum Filter {
     Min,
     String,
     Sum,
+    Truncate,
     Upper,
     WordCount,
 }
@@ -37,6 +38,7 @@ impl Filter {
             "min" => Ok(Filter::Min),
             "string" => Ok(Filter::String),
             "sum" => Ok(Filter::Sum),
+            "truncate" => Ok(Filter::Truncate),
             "upper" => Ok(Filter::Upper),
             "wordcount" => Ok(Filter::WordCount),
             _ => todo!(),
@@ -55,7 +57,6 @@ impl Filter {
             Filter::Escape => base_value.escape(),
             Filter::First => base_value.first(),
             Filter::Int => Ok(Value::Integer(base_value.int()?)), // TODO change to accept parameters
-
             Filter::Float => Ok(Value::Double(base_value.float()?)), // TODO change to accept parameters
             Filter::Last => base_value.last(),
             Filter::Length => Ok(Value::Integer(base_value.len()? as i64)),
@@ -64,6 +65,7 @@ impl Filter {
             Filter::Min => base_value.min(), // TODO Accept params
             Filter::String => Ok(Value::String(base_value.to_string())),
             Filter::Sum => base_value.sum(), // TODO: ACcept params
+            Filter::Truncate => base_value.truncate(params, context),
             Filter::Upper => base_value.upper(),
             Filter::WordCount => base_value.wordcount(),
         }

src/value/filters.rs

@@ -3,6 +3,7 @@ use crate::context::Context;
 use crate::error::{Error, ErrorKind, Result};
 use crate::expression_evaluator::CallParams;
 use crate::expression_evaluator::Evaluate;
+use std::convert::TryInto;
 
 use regex::Regex;
 
@@ -176,6 +177,31 @@ impl Value {
             Err(Error::from(ErrorKind::InvalidOperation))
         }
     }
+    pub fn truncate(self, params: &Option<CallParams>, context: Context) -> Result<Self> {
+        let mut string_value = self.to_string();
+
+        let size = match params {
+            None => 150,
+            Some(call_params) => {
+                if let Some(value) = call_params.kw_params.get("length") {
+                    value.evaluate(context)?.int()?.try_into().unwrap()
+                } else if let Some(value) = call_params.pos_params.first() {
+                    value.evaluate(context)?.int()?.try_into().unwrap()
+                } else {
+                    150
+                }
+            }
+        };
+        let value = if string_value.len() > size {
+            string_value.truncate(size - 3);
+            string_value.push_str("...");
+            string_value
+        } else {
+            string_value
+        };
+        Ok(Value::String(value))
+    }
+
     pub fn upper(self) -> Result<Self> {
         match self {
             Value::String(s) => Ok(Value::String(s.to_uppercase())),

tests/filters.rs

@@ -150,3 +150,9 @@ fn default_filter() -> Result<()> {
     )?;
     assert_render_template_eq("{{ undefined | default }}", "", Some(context.clone()))
 }
+#[test]
+fn truncate_filter() -> Result<()> {
+    assert_render_template_eq("{{ ('a' * 20) | truncate(10) }}", "aaaaaaa...", None)?;
+    assert_render_template_eq("{{ ('a' * 20) | truncate(length=10) }}", "aaaaaaa...", None)?;
+    assert_render_template_eq("{{ ('a' * 20) | truncate }}", "aaaaaaaaaaaaaaaaaaaa", None)
+}